This invention relates to means for preforming electrical components prior to mounting them in a circuit board or the like. More specifically, this invention relates to apparatus for cutting and preshaping the wire leads of electrical components to a desired configuration.
As is well known in the art, a number of machines are presently available which are capable of preparing electrical components, such as resistors or capacitors, prior to their being mounted in circuit boards, chassis or the like. Typically, the component will include a cylindrical body section from whose end walls axially extend a pair of wire leads or pig-tail connections. Depending upon its intended use, the wire leads are usually precut by the machine to a prescribed length and the leads then crimped or preshaped to a desired form. Conventionally, the final form involves a U-shaped arrangement wherein the body section of the component is located along the base leg of the structure. A machine of this type is disclosed by Dolder in U.S. Pat. No. 3,596,486.
In order to increase productivity, and to eliminate to some extent human error, many existing machines are adapted to accept a taped input wherein the components are supported in spaced parallel alignment by means of adhesive strips that are arranged to engage the two outer extremities of the leads. The tape supply is generally wound upon a spool and, as described by Dolder, the tape threaded upon a drive mechanism containing a number of coacting sprocket wheels which engage the component leads. In operation, the drive advances the work past cutting and forming tools to carry out the desired operations. The severed taped ends of the leads are ejected from the machine while the formed components are collected within a bin.
Oftentimes, however, it is desirous or necessary to hand load individual components into the machine when small quantities of components are needed. In this type of application, the electrical elements are fed one at a time into the drive sprockets using an entry chute adapted to properly position and align the elements for proper engagement by the drive.
Heretofore, machines that were specifically designed for a taped input were not necessarily compatible for use in conjunction with a manual input. Typically, the teeth of the drive sprocket wheels are provided with a deep contour to securely engage and positively seat the leads therebetween to insure proper engagement with the processing tools. The deep sprocket tooth contour, although well suited to act in conjunction with a taped lead input may nevertheless be unreliable when handling loose individual elements. An improperly seated or misaligned component can be drawn into a work station where it might become jammed and cause injury to the machine.
Moreover, in many sprocket drive machines, the positioning of the work stations is restricted to locations above the horizontal centerline of the drive to prevent the electrical components from prematurely falling out of the teeth while they are in transit. This, of course, restricts the amount of usable space afforded, limits the flexibility of machine design and requires, generally, that the machine be overly large in size.